OPTIMAL CONTROL METHOD FOR ASYNCHRONOUS TRACTION MOTORS OF AUTONOMOUS LOCOMOTIVES, BASED ON CONTROLLING SLIP FREQUENCY

摘要

The invention relates to a method for controlling asynchronous traction motors of autonomous locomotives. According to the invention, the method is based on the fact that, at any stationary point of operation of the asynchronous motor, there is an optimal value of the slip frequency which maximizes the efficiency of the motor and the dependence of the optimal slip frequency in relation to the speed, at constant current, is linear on two domains of the speed variation, on the fact that the dynamic acceleration or deceleration processes, with the accelerations required by the vehicle, are also obtained by controlling the rotor slip frequency, by forcing the optimal values corresponding to the stationary regime, also resulting in a linear variation, and on the modality to change the rotor slip frequency when switching from dynamic regime to stationary regime and vice versa, so that there are no impermissible dynamic shocks, the method comprising the decomposing of the transient mode into two stages: heavy transient mode, when the relative speed error (ε) exceeds an imposed limit (ε), and light transient mode, when the relative speed error is equal to or below the imposed limit.